KR20080072339A - Method of manufacturing thin film transistor array panel - Google Patents

Abstract

A method for manufacturing a thin film transistor substrate is provided to form an organic semiconductor having an interfacial characteristic with a gate insulating layer, by injecting an organic semiconductor solution, which is obtained by dissolving an organic semiconductor material in organic solvent, into an opening and drying the organic semiconductor solution under vacuum atmosphere. A gate line(121) is formed on an insulating substrate(110), wherein the gate line includes a gate electrode(124) and an end portion(129). A gate insulating layer(140) is formed on the substrate and the gate line. A data line(171) and a drain electrode(175) are formed on the gate insulating layer, wherein the data line includes a source electrode(173) and an end portion(179). A passivation layer(180) is formed on the data line, the drain electrode, and the gate insulating layer. A plurality of contact holes(181,182,185) and an opening(184) are formed in the passivation layer. An organic semiconductor solution is injected into the opening through an inkjet printing method using a nozzle. The organic semiconductor solution contains an organic semiconductor material, a first organic solvent of solid state, and a second organic solvent. The first organic solvent has a melting point higher than the normal temperature. The second organic solvent has a higher solubility than the first organic solvent. The resultant substrate is transferred in a drying chamber. Meanwhile, the organic semiconductor solution exposed to the air is firstly dried under the normal temperature to form a preliminary organic semiconductor. The preliminary organic semiconductor is dried to form an organic semiconductor(154) by heating the resultant substrate to a temperature above the melting point of the first organic solvent under steam atmosphere within the chamber. The organic semiconductor has an interfacial characteristic with the gate insulating layer and a uniform thickness. A protection member(186) is formed on the organic semiconductor. Auxiliary contact members(81,82) and a pixel electrode(191) are formed on the passivation layer.

Description

Method of manufacturing thin film transistor array panel {METHOD OF MANUFACTURING THIN FILM TRANSISTOR ARRAY PANEL}

1 is a layout view of a thin film transistor array panel according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of the thin film transistor array panel of FIG. 1 taken along the line II-II.

3 is a layout view at an intermediate stage of a method of manufacturing the thin film transistor array panel of FIG. 1 according to an embodiment of the present invention;

4 is a cross-sectional view of the thin film transistor array panel of FIG. 3 taken along the line IV-IV.

FIG. 5 is a layout view of a thin film transistor array panel in the next step of FIG. 3;

FIG. 6 is a cross-sectional view of the thin film transistor array panel of FIG. 5 taken along the line VI-VI.

FIG. 7 is a layout view of a thin film transistor array panel in the next step of FIG. 5;

FIG. 8 is a cross-sectional view of the thin film transistor array panel of FIG. 7 taken along the line VIII-VIII.

9 to 11 are cross-sectional views in an intermediate step of manufacturing the thin film transistor array panel of FIG. 12.

FIG. 12 is a layout view of a thin film transistor array panel in the next step of FIG. 7;

FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XII-XII.

 <Description of Drawing>

110: insulating substrate 121: gate line

124: gate electrode 129: end of gate line

140: gate insulating film 154: organic semiconductor

171: data line

172, 176: horizontal section 174, 177: vertical section

173: source electrode 175: drain electrode

180: protective film 191: pixel electrode

81, 82: contact auxiliary members 181, 182, and 185: contact holes

Q: channel of thin film transistor

The present invention relates to a thin film transistor array panel and a method of manufacturing the same.

In general, a flat panel display device such as a liquid crystal display (LCD), an organic light emitting device (OLED), an electrophoretic display, or the like, includes a plurality of pairs of electric field generating electrodes It contains an electro-optical active layer. The liquid crystal display device includes a liquid crystal layer as the electro-optical active layer, and the organic light emitting display device includes an organic light emitting layer as the electro-optical active layer.

One of the pair of field generating electrodes is typically connected to a switching element to receive an electrical signal, and the electro-optical active layer converts the electrical signal into an optical signal to display an image.

In the flat panel display device, a thin film transistor (TFT), which is a three-terminal element, is used as a switching element. A data line to be transmitted is provided in the flat panel display.

Among these thin film transistors, studies on organic thin film transistors (OTFTs) including organic semiconductors instead of inorganic semiconductors such as silicon (Si) have been actively conducted.

The organic thin film transistor may be manufactured through a liquid crystal process at a low temperature without a vacuum or a high temperature treatment process. This enables mass production and reduces the process costs of the product.

The organic semiconductor (OSC) of the organic thin film transistor forms a partition wall surrounding a region where the organic semiconductor OSC is to be formed, like a bank, and an inkjet (hereinafter, referred to as an opening) surrounded by the partition wall. After filling the organic solution through an inkjet process, the substrate is transferred to a chamber for a drying process for drying the organic solution, and the organic solution is formed by drying the organic solution in a vapor atmosphere.

However, when transporting the substrate, part of the organic solution evaporates to form an organic film on the upper surface of the organic solution.

This organic film prevents the organic solution existing below from being slowly dried by the vapor in the chamber. As a result, a complete organic semiconductor may not be formed and electrical characteristics of the thin film transistor may be degraded.

Accordingly, an object of the present invention is to improve the electrical characteristics of a thin film transistor.

According to an exemplary embodiment of the present invention, a thin film transistor array panel includes: forming a gate wiring including a gate electrode on a substrate, forming a gate insulating film on the gate wiring, and forming a gate wiring on the gate insulating film; Forming an electrode, forming a protective film on the gate insulating film, the data line and the drain electrode, etching the protective film to form an opening and a contact hole exposing the source electrode and the drain electrode, wherein the protective film is formed in the opening; Injecting an organic semiconductor solution by inkjet printing, and drying the organic semiconductor solution to form an organic semiconductor, wherein the organic semiconductor solution comprises an organic semiconductor material, a first organic solvent in a solid state, and the solid state Second to dissolve the first organic solvent of Organic solvents.

Drying the organic semiconductor solution to form an organic semiconductor may include transferring the substrate into a chamber, and placing the substrate above a melting point of the first organic solvent in the solid state in a state of forming a vapor atmosphere in the chamber. Heating may be included.

The first organic solvent is cyclohexanol, bibenzyl, 2,5-dibromo-p-xylene, 3,5-dibromo -Toluene (3,5-dibromo-toluene), 2-chloro-5-methylphenol, 4-chloro-2-methylphenol, 3- Chloro-3-methylphenol, 5-chloro-2-methylphenol, 1-phenylpyrrole, 4H-pyran-4- Circle (4H-pyran-4-one), 2,4,6-trichloropyrimidine (2,4,6-trichlorropyrimidine), 2,3,4-trimethyl-1 (2,3,4-Trimethyl-1 ), 3-pentanediol, decafluorobiphenyl, 1,4-di-t-butylbenzene, 2,6-di-t-butyl- 4 ethylphenol (1,4-di-tert-buthyl-ethylphenol), 2,6-di-t-butyl-4-methylpyridine (2,6-di-tert-buthyl-4-methylpyridine), 2,6 -Di-t-butylphenol (2,6-di-tert-buthylphenol), 2,4-di-t-butylphenol (1,4-di-tert-buthylphenol), 2,5-dichloroaniline (2, 5-dichloroaniline) and 3,5-dichloro Of aniline (3,5-dichloroaniline) may be formed of at least one material.

The second organic solvent that dissolves the first organic solvent may be made of any one material of tetralin and anisol.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a portion of a layer, film, region, plate, etc. is said to be "on top" of another part, this includes not only when the other part is "right over" but also when there is another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a thin film transistor array panel according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

1 is a layout view of a thin film transistor array panel according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the thin film transistor array panel of FIG. 1 taken along line II-II.

The gate line 121 is formed on an insulating substrate 110 made of transparent glass, silicon, or plastic.

The gate line 121 transmits a gate signal and mainly extends in a horizontal direction. Each gate line 121 includes a plurality of gate electrodes 124 protruding upwards and a wide end portion 129 for connection with another layer or an external driving circuit. A gate driving circuit (not shown) that generates a gate signal is mounted on a flexible printed circuit film (not shown) attached over the substrate 110, directly mounted on the substrate 110, or integrated into the substrate 110. Can be. When the gate driving circuit is integrated on the substrate 110, the gate line 121 may extend to be directly connected to the gate driving circuit.

The gate line 121 may be formed of aluminum-based metal such as aluminum (Al) or aluminum alloy, silver-based metal such as silver (Ag) or silver alloy, gold-based metal such as gold (Au) or gold alloy, copper (Cu), copper alloy, etc. Copper-based metals, molybdenum-based metals such as molybdenum (Mo) and molybdenum alloys, low-resistance conductors such as chromium (Cr), tantalum (Ta) and titanium (Ti), or indium tin oxide (ITO) and indium zinc oxide (IZO) It may be made of a conductive oxide such as. However, they may have a multilayer structure including two conductive films (not shown) having different physical properties.

The gate line 121 may be inclined at an inclined angle of about 30 ° to about 80 ° with respect to the surface of the substrate 110.

The gate insulating layer 140 is formed on the gate line 121. The gate insulating layer 140 may be made of an organic material or an inorganic material. Examples of the organic material may include polyimide, polyvinyl alcohol, polyfluorane, parylene, and the like. A soluble high molecular compound is mentioned, An example of an inorganic substance is a silicon oxide surface-treated with octadecyl trichlorosilane (OTS).

A data line 171 and a drain electrode 175 are formed on the gate insulating layer 140.

The data line 171 transmits a data signal and mainly extends in the vertical direction to cross the gate line 121. Each data line 171 includes a wide end portion 179 for connecting a source electrode 173 protruding to the side and another layer or an external driving circuit. A data driving circuit (not shown) for generating a data signal is mounted on a flexible printed circuit film (not shown) attached to the substrate 110, directly mounted on the substrate 110, or integrated in the substrate 110. Can be.

The source electrode 173 includes a horizontal portion 172 connected to the data line 171 and a vertical portion 174 overlapping the gate electrode 124.

The drain electrode 175 is island-shaped and includes a vertical portion 177 facing the vertical portion 174 of the source electrode 173 and a horizontal portion 176 extending laterally from the gate electrode 124.

Like the gate line 121, the data line 171 and the drain electrode 175 may be made of a low resistance conductor or a conductive oxide.

Side surfaces of the data line 171 and the drain electrode 175 may be inclined at an inclination angle of about 30 ° to 80 ° with respect to the surface of the substrate 110.

A passivation layer 180 having a plurality of contact holes 181, 182, and 185 and an opening 184 is formed on the data line 171, the drain electrode 175, and the gate insulating layer 140. The passivation layer 180 may be made of an organic insulating material or an inorganic insulating material.

The contact holes 181, 182, and 185 expose the end portion 129 of the gate line 121, the end portion 179 of the data line 171, and the drain electrode 175, respectively, and the openings 184 may be adjacent to each other. The source electrode 173 and the drain electrode 175 facing each other and the gate insulating layer 140 exposed therebetween are exposed.

An organic semiconductor 154 formed by inkjet printing is formed in the opening 184 of the passivation layer 180. In this case, the organic semiconductor 154 has a uniform thickness and has good adhesion with the gate insulating layer 140.

The organic semiconductor 154 includes pentacene and its precursors, tetrabenzoporphyrin and its derivatives, polyphenylenevinylene and its derivatives, polyfluorene and its derivatives, and polytinylene vinyl. Polythienylenevinylene and its derivatives, polythiophene and its derivatives, polythienothiophene and its derivatives, polyarylamine and its derivatives, phthalocyanine and its derivatives, metallized phthalocyanine (metallized phthalocyanine) or halogenated derivatives thereof, perylenetetracarboxylic dianhydride (PTCDA), naphthalenetetracarboxylic dianhydride (NTCDA) or imide derivatives thereof, perylene or It may be made of at least one selected from derivatives including coronene and their substituents. have.

The protection member 186 is formed on the organic semiconductor 154. The protection member 186 is made of a fluorine-based hydrocarbon compound or a polyvinyl alcohol-based compound, and protects the organic semiconductor 154 from external heat, plasma, or chemicals.

One gate electrode 124, one source electrode 173, and one drain electrode 175 form one thin film transistor together with the organic semiconductor 154, and the channel Q of the thin film transistor is a source. An organic semiconductor 154 is formed between the electrode 173 and the drain electrode 175. In this case, the portions of the source electrode 173 and the drain electrode 175 facing each other may be bent to increase the channel width to improve current characteristics.

The contact auxiliary members 81 and 82 and the pixel electrode 191 are formed on the passivation layer 180 and the contact holes 181, 182, and 185.

The pixel electrode 191 is connected to the drain electrode 175 through the contact hole 185. The pixel electrode 191 receives an data voltage from the drain electrode 175 and generates an electric field together with a common electrode (not shown) of another display panel (not shown) to which a common voltage is applied. This determines the direction of the liquid crystal molecules of the liquid crystal layer (not shown) between the two electrodes. The pixel electrode 191 and the common electrode form a capacitor (hereinafter, referred to as a "liquid crystal capacitor") to maintain an applied voltage even after the thin film transistor is turned off.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 and the external device.

The pixel electrode 191 and the contact assistants 81 and 82 are made of a transparent conductive material such as IZO or ITO.

 Next, a method of manufacturing the organic thin film transistor array panel illustrated in FIGS. 1 and 2 will be described in detail with reference to FIGS. 3 to 13.

3 is a layout view at an intermediate stage of the method of manufacturing the thin film transistor array panel of FIG. 1 according to an exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view of the thin film transistor array panel of FIG. 3 taken along line IV-IV. 5 is a layout view of a thin film transistor array panel in a next step of FIG. 3, and FIG. 6 is a cross-sectional view of the thin film transistor array panel of FIG. 5 taken along a line VI-VI, and FIG. FIG. 8 is a cross-sectional view of the thin film transistor array panel of FIG. 7 taken along the line VIII-VIII, and FIGS. 9 to 11 are cross-sectional views at an intermediate stage of manufacturing the thin film transistor array panel of FIG. 12 is a layout view of a thin film transistor array panel of the next step of FIG. 7, and FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XII-XII.

First, as illustrated in FIGS. 3 and 4, a conductive layer is sputtered on the insulating substrate 110 and then photo-etched to form a gate line including a gate electrode 124 and an end portion 129. (121) is formed.

Next, as shown in FIGS. 5 and 6, after the gate insulating layer 140 is stacked on the substrate 110 and the gate line 121, a conductive layer is stacked on the substrate 110, and the source electrode 173 is photo-etched. And a data line 171 and a drain electrode 175 including an end portion 179.

Next, as shown in FIGS. 7 and 8, the passivation layer 180 is formed on the data line 171, the drain electrode 175, and the gate insulating layer 140. Here, the passivation layer 180 may be made of an inorganic insulator or an organic insulator and may have a flat surface.

Subsequently, the passivation layer 180 is formed using a photolithography process to form the plurality of contact holes 181, 182, and 185 and the openings 184.

Next, as shown in FIG. 9, the organic semiconductor solution 5 is injected into the opening 184 by an inkjet printing method using the nozzle 40. Here, the organic semiconductor solution 5 includes an organic semiconductor material and a first organic solvent in a solid state having a melting point higher than room temperature and a second organic solvent having high solubility in the first organic solvent.

Organic semiconductor materials include pentacene and its precursors, tetrabenzoporphyrin and its derivatives, polyphenylenevinylene and its derivatives, polyfluorene and its derivatives, and polytinylenevinylene polythienylenevinylene and its derivatives, polythiophene and its derivatives, polythienothiophene and its derivatives, polyarylamine and its derivatives, phthalocyanine and its derivatives, metallized phthalocyanines phthalocyanine or its halogenated derivatives, perylenetetracarboxylic dianhydride (PTCDA), naphthalenetetracarboxylic dianhydride (NTCDA) or imide derivatives thereof, perylene or coronene at least one selected from derivatives containing coronene and their substituents. There.

The first organic solvent in the solid state is cyclohexanol, bibenzyl, 2,5-dibromo-p-xylene, 3,5-di Bromo-toluene (3,5-dibromo-toluene), 2-chloro-5-methylphenol, 4-chloro-2-methylphenol, 3-chloro-3-methylphenol, 5-chloro-2-methylphenol, 1-phenylpyrrole, 4H-pyran- 4-membered (4H-pyran-4-one), 2,4,6-trichloropyrimidine (2,4,6-trichlorropyrimidine), 2,3,4-trimethyl-1 (2,3,4-Trimethyl -1), 3-pentanediol, decafluorobiphenyl, 1,4-di-t-butylbenzene, 2,6-di-t- Butyl-4ethylphenol (1,4-di-tert-buthyl-ethylphenol), 2,6-di-t-butyl-4-methylpyridine (2,6-di-tert-buthyl-4-methylpyridine), 2 , 6-di-t-butylphenol (2,6-di-tert-buthylphenol), 2,4-di-t-butylphenol (1,4-di-tert-buthylphenol), 2,5-dichloroaniline ( 2,5-dichloroaniline) and 3,5- Dichloroaniline (3,5-dichloroaniline) may be composed of at least one material selected from.

The second organic solvent may be composed of at least one material selected from materials such as tetralin and anisol.

These first and second organic solvents dissolve the organic semiconductor material without chemically reacting with the organic semiconductor material.

On the other hand, when the solubility of the second organic solvent in the organic semiconductor material is not high, a third organic solvent having high solubility in the organic semiconductor material may be added.

Next, as shown in FIG. 10, the substrate 100 is transferred into a chamber for drying the organic solution. In this process, the organic semiconductor solution 5 exposed to air is primarily dried at room temperature. At this time, a second organic solvent having a high volatility and a melting point lower than room temperature is preliminarily volatilized among the materials constituting the organic semiconductor solution 5. The organic semiconductor 50 is formed.

When only an organic solvent in a liquid state at room temperature is used, the organic solution exposed to room temperature evaporates during substrate transfer to form an organic film on the upper surface of the organic solution. However, in the exposed preliminary organic semiconductor 50 of the present invention, since the first organic solvent in the solid state does not volatilize and is present with the organic semiconductor material, no organic layer is formed during substrate transfer. Subsequently, as illustrated in FIG. 11, the substrate 110 is heated above the melting point of the first organic solvent in a vapor atmosphere in the chamber to dry the preliminary organic semiconductor 50. As the preliminary organic semiconductor 50 is dried in the vapor atmosphere as described above, the first organic solvent in the solid state is slowly and evenly evaporated.

On the other hand, when using only the organic solvent in the liquid state at room temperature, the above-described organic film blocks the contact of the vapor and the organic solvent in the chamber. As a result, the organic solvent is non-uniformly dried within a short time by heat transferred to the substrate. As a result, the interface characteristics between the gate insulating film and the organic semiconductor may be degraded, and the electrical characteristics of the thin film transistor may be degraded.

However, in the present invention, the preliminary organic semiconductor 50 is uniformly contacted with the vapor to dry the preliminary organic semiconductor 50 slowly. As a result, as shown in FIGS. 12 and 13, an organic semiconductor 151 having a good interface characteristic with the gate insulating layer 140 and having a uniform thickness is formed. Thus, the electrical characteristics of the thin film transistor can be improved.

Finally, as shown in FIGS. 1 and 2, the protection member 186 is formed on the organic semiconductor 154. The protective member 186 is made of a fluorine-based hydrocarbon compound or a polyvinyl alcohol-based compound, and protects the organic semiconductor 154 from external heat, plasma, or chemicals.

Then, a transparent conductive film such as ITO or IZO is formed on the passivation layer 180 and the contact holes 181, 182, and 185, and patterned to form the contact auxiliary members 81, 82 and the pixel electrode 191. In this case, the contact auxiliary members 81 and 82 are electrically connected to the end portions 129 of the gate lines 121 and the end portions 179 of the data lines 171 exposed through the contact holes 181 and 182, respectively. To achieve. The pixel electrode 191 is electrically connected to the drain electrode 175 exposed through the contact hole 185.

According to the present invention, an organic semiconductor solution formed by dissolving an organic semiconductor in a solvent comprising a solid organic first solvent and a second organic solvent having high solubility in the first organic solvent is injected into the opening by inkjet printing, and then dried. The substrate is transferred into the substrate, and the organic semiconductor solution is dried in a vacuum atmosphere to form an organic semiconductor having good interfacial properties with the gate insulating film. Accordingly, the electrical characteristics of the thin film transistor may be improved.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the present invention.

Claims (4)

Forming a gate wiring including a gate electrode on the substrate, Forming a gate insulating film on the gate wiring; Forming a data line and a drain electrode including a source electrode on the gate insulating layer; Forming a passivation layer on the gate insulating layer, the data line and the drain electrode; Etching the passivation layer to form openings and contact holes exposing the source electrode and the drain electrode; Injecting an organic semiconductor solution into the opening by inkjet printing; and Drying the organic semiconductor solution to form an organic semiconductor Including; And the organic semiconductor solution comprises an organic semiconductor material, a first organic solvent in a solid state, and a second organic solvent in which the first organic solvent in the solid state is dissolved. In claim 1, Drying the organic semiconductor solution to form an organic semiconductor may include transferring the substrate into a chamber, wherein the substrate is above the melting point of the first organic solvent in the solid state in a state of making the chamber into a vapor atmosphere. Method of manufacturing a thin film transistor array panel comprising the step of heating. In claim 1, The first organic solvent is cyclohexanol, bibenzyl, 2,5-dibromo-p-xylene, 3,5-dibromo -Toluene (3,5-dibromo-toluene), 2-chloro-5-methylphenol, 4-chloro-2-methylphenol, 3- Chloro-3-methylphenol, 5-chloro-2-methylphenol, 1-phenylpyrrole, 4H-pyran-4- Circle (4H-pyran-4-one), 2,4,6-trichloropyrimidine (2,4,6-trichlorropyrimidine), 2,3,4-trimethyl-1 (2,3,4-Trimethyl-1 ), 3-pentanediol, decafluorobiphenyl, 1,4-di-t-butylbenzene, 2,6-di-t-butyl- 4 ethylphenol (1,4-di-tert-buthyl-ethylphenol), 2,6-di-t-butyl-4-methylpyridine (2,6-di-tert-buthyl-4-methylpyridine), 2,6 -Di-t-butylphenol (2,6-di-tert-buthylphenol), 2,4-di-t-butylphenol (1,4-di-tert-buthylphenol), 2,5-dichloroaniline (2, 5-dichloroaniline) and 3,5-dichloro Aniline (3,5-dichloroaniline) method for producing a TFT array panel consisting of at least one material selected from the group consisting of. In claim 1, The second organic solvent for dissolving the first organic solvent is a method of manufacturing a thin film transistor array panel made of a material of any one of tetralin and anisol.

Images